Functional Analytic Psychotherapy was developed from radical behavioral theory. The theoretical foundations of the therapy are that there are classes of behavioral excesses and deficits that contribute to interpersonal poor functioning. In many cases these problem behaviors and resulting ineffective ways of relating to the environment can lead to anxiety or depressive symptoms. If the problems are longstanding, there may evidence of personality disorders. These problems are often seen as indications for the prescription of benzodiazapines by primary care physicians that may lead to benzodiazapine misuse. This application applies FAP to a sample of benzodiazapine dependent subjects in the context of a treatment development study. Though FAP has a strong theoretical foundation, this proposal is one of the first empirical tests of the principles behind FAP. We have developed a coding and training system for studying FAP. We propose to test FAP using an innovative Theory Driven Research Design we have explicated elsewhere that tests not only if therapy works, but by what mediating mechanisms. We propose a set of plausible causal paths to benzodiazapine dependence that FAP will test. This project combines radical behavioral theory to a significant drug abusing population in a research context that tests basic behavioral principles, theory, and adherence. The study proposes to combine a 20 week FAP intervention with a drug tapering protocol in 30 patients. The purpose of the study will be to develop and refine the treatment so it is replicable and trainable in additional studies.